Image copyrightZeitImage caption
The German publishers challenged AdBlock Plus's right to suppress ads on their web pages

The creator of software that stops adverts from appearing on websites has defeated two news publishers that want to prevent its tech being used on their pages.

The owners of Germany's Die Zeit and Handelsblatt had claimed that AdBlock Plus's product was anti-competitive and threatened their ability to make money.

But a court in Hamburg ruled that users do have the right to use the plug-in.

The judgement has implications for other disputes involving the tool.

"The Hamburg court decision is an important one because it sets a precedent that may help us avoid additional lawsuits and expenses defending what we feel is an obvious consumer right: giving people the ability to control their own screens by letting them block annoying ads and protect their privacy," wrote AdBlock Plus's project manager, Ben Williams, on its blog.

"Now that the legalities are out of the way, we want to reach out to other publishers and advertisers and content creators and encourage them to work with Adblock Plus rather than against us."

However, the publishers have indicated that they intend to fight on.

"We are still convinced that AdBlock Plus is an illegal and anti-competitive practice," they said in a joint statement.

Image copyrightAdblock PlusImage caption
AdBlock Plus offers its service as a free plug-in for popular web browsers

"It infringes the freedom of the press. Therefore, we will await the written reasons for the judgment, analyse them and examine the prospects of an appeals procedure."

It highlights that its service has proved popular with many users, with AdBlock Plus having been downloaded nearly 400 million times.

It also notes that it does not charge fees to smaller businesses and blogs, and allows users to block its white-listed ads if desired.

"If we are racketeers we are terrible racketeers because 90% of the people on the white list don't pay anything and the criteria is the same for everyone," Mr Williams told the BBC.

Image copyrightHandelsbattImage caption
Handelsbatt says AdBlock Plus's suppression of ads on its sites should not be permitted

"[The ruling] is living proof of the unalienable right of every user to enjoy online self-determination."

However, one lawyer, who is not involved in the German cases, noted that other European courts might not necessarily take the same view.

"The Hamburg court based its decision on the provisions of EU Law... other national courts in EU member states must do likewise, but are not bound to reach the same legal conclusions," said Paul Henty from the law firm Charles Russell Speechlys.

"There could also be different factual or economic circumstances in those jurisdictions which lead to a different result.

"Nonetheless, the Hamburg judgment may be persuasive as an authority and will certainly be a boon to Eyeo in similar AdBlock disputes."